First half tries to Aidan Guerra, Michael Jennings and Shaun Kenny-Dowall helped the visitors to a 16-6 halftime lead after the Warriors managed just one four-pointer to Sam Tomkins, despite enjoying a wealth of attacking possession inside the opposition red zone.
"I thought we lacked a bit of conviction with our play there. We had a plan that I think would have worked but I didn't see much of that but there were lots of other disappointing areas as well," said McFadden.
A dislocated shoulder ended Warriors winger David Fusitu'a's afternoon after five minutes, meaning Ben Henry had to shift out wide, with centre Ngani Laumape filling in on the flank to leave their bench a man down.
The second-half saw the Roosters forwards assert their dominance and quick tries followed to captain Anthony Minichiello and Sam Moa, before a senseless flop saw Warriors lock Sebastine Ikahihifo sinbinned. The Roosters capitalised further, with Isaac Liu, and Boyd Cordner both touching down, before Laumape scored the Warriors second. The Roosters had the last word when Jennings claimed his second, while former Warrior James Maloney kicked seven goals in an outstanding all-round personal game.
Captain Simon Mannering said his team struggled up-front and had no response to the Roosters second-half roll-on. With Kiwis test contenders Jared-Waerea-Hargreaves, Frank Paul Nuuausala and Sam Moa leading the way, and halves Mitchell Pearce and Maloney playing at the line, the Roosters continually found room on the edges of the ruck. Their back-row trio of Williams, Cordner and Guerra played off the back of that momentum and the Warriors forwards were found wanting.
"First set they marched us the whole field and we were at sixes and sevens defensively. It starts in the middle with us forwards and we didn't match that intensity," Mannering said.
Less than a month ago the Warriors were within range of the top four but consecutive defeats have dropped them down into 10th spot on the NRL ladder. McFadden conceded they are now in a must-win predicament ahead of their final games against the Titans and Panthers.
"We are going to have to win both games and then maybe even require some other results to go our way [to make the top eight]."
Warriors 12 (Sam Tomkins, Ngani Laumape tries; Shaun Johnson 2 from 2 goals)
Roosters 46 (Aidan Guerra, Michael Jennings 2, Anthony Minichiello, Sam Moa, Shaun Kenny-Dowall, Isaac Liu, Boyd Cordner tries; Maloney seven conversions)